A heat pump dishwasher

ABSTRACT

The present invention relates to a dishwasher comprising a body; a tub; a drying pocket disposed at least one lateral wall of the tub, that is in thermal contact with the tub and that provides the condensation of the humid air inside the tub by being cooled in the drying step; a heat pump disposed inside the body, that provides the heating of the water to be used in the washing step and that has a first heat exchanger drawing heat from the ambient air, a second heat exchanger transferring the heat received from the first heat exchanger to the wash water and a compressor fluidly connected to the first heat exchanger and the second heat exchanger, realizing the refrigerant cycle, and a drip tray disposed immediately under the first heat exchanger, wherein the water condensing on the first heat exchanger is collected.

The present invention relates to a dishwasher comprising a heat pumpproviding the heating of the water to be used in washing.

In dishwashers, heating the water used for washing and rinsing thedishes to be used by heat pumps with low energy consumption is known.The heat pumps are operated with the principle that the refrigerant iscompressed and expanded between at least two heat exchangers, thusproviding heat transfer. In addition, heat is drawn from the environmentor from an additional heat source such as heat reservoir by the heatexchanger and the heat drawn is transferred to the other heat exchanger,thus increasing the effectiveness of the heat pump. Since the surface ofthe heat exchanger that draws heat from the environment is cold, themoisture in the ambient air condenses on the heat exchanger. Drip trayswherein the condensate is collected are used under the heat exchanger.If the water collected in the drip tray is not discharged, it causes badodors and moreover, when the tray is overflown, the overflown watercauses electrical failures.

In the state of the art European Patent Application No. EP2682037, adishwasher is disclosed, wherein the condensate is discharged togetherwith the wash water.

In the state of the art International Patent Application No.WO2005009197, a dishwasher is disclosed, wherein the drying efficiencyis improved by using the wash water.

In the state of the art International Patent Application No.WO2012089569, a dishwasher is disclosed, comprising a heat exchangerconnected to a cold reservoir, wherein the heat stored in the coldreservoir is used in the drying step.

The aim of the present invention is the realization of a dishwasherwherein the water condensing on the heat exchanger is efficientlydischarged.

The dishwasher realized in order to attain the aim of the presentinvention, explicated in the first claims and the respective claimsthereof comprises a water duct that extends between the drip tray andthe drying pocket disposed on the tub lateral surface; a pump that isdisposed on the water duct and that enables the water in the drip trayto be delivered to the drying pocket; a hole that opens into the tub atthe base of the drying pocket and a control unit that enables the waterin the drip tray to be discharged through the drying pocket by means ofthe pump. In the dishwasher of the present invention, the watercollected in the drip tray is transferred to the drying pocket, thatenables the humid air inside the tub to be condensed after the washingprocess, thus providing the cooling of the drying pocket. Thus, by usingthe cold water in the drip tray, savings in the energy required for thedrying process are provided.

In an embodiment of the present invention, the drying pocket is cooledby circulating the water in the drip tray through a channel, that isdisposed at the lateral surface of the drying pocket and that has aninlet providing the intake of the water transferred to the drying pocketand an outlet providing the transfer thereof to the tub through thehole, thus providing the discharge of the water. In this embodiment, thewater is passed through a channel instead of the drying pocket whereinthe condensation occurs and thus, the water providing the cooling isprevented from leaving its moisture on the surface where thecondensation occurs. Consequently, the hot humid air coming from the tubis enabled to be more efficiently condensed on the surfaces of thedrying pocket.

In another embodiment of the present invention, the channel is arrangedon at least one surface of the tub wherein the washing process iscarried out. By disposing the channel on the lateral surface of the tub,the lateral surface of the tub is cooled, thus causing the formation ofcondensation on the lateral surface of the tub and increasing the dryingefficiency.

In another embodiment of the present invention, the channel is bent inserpentine form on the tub surface. By increasing the length of thechannel as such, the cold water in the drip tray is discharged afterflowing a longer path and by increasing the surface area being cooled,the amount of heat transfer is increased.

In another embodiment of the present invention, the channel surroundsall around the tub. By means of this embodiment, the cold water in thedrip tray enables the cooling of almost the entire tub surface. Thus,the humid air in the tub condenses on all the surfaces of the tub.

In another embodiment of the present invention, a first valve at thechannel inlet and a second valve at the channel outlet are provided toenable the opening/closing of the channel inlet and outlet and after thewater in the drip tray is transferred to the channel, the valves arechanged to the closed position, thus enabling the water transferred fromthe drip tray to be kept waiting in the channel.

In another embodiment of the present invention, the control unit keepsthe first valve and the second valve closed in order to increase theamount of the heat transfer of the channel surfaces with the waterflowing through the channel, thus by increasing the duration the waterperforms heat transfer with the channel, the drying pocket is moreefficiently cooled.

In another embodiment of the present invention, the water transferredinto the channel is circulated through the channel by means of acirculation pump. The control unit changes the first valve and thesecond valve to the closed position and the circulation pump circulatesthe water through the channel, thus enabling the channel to beefficiently cooled.

In another embodiment of the present invention, the dishwasher comprisesan opening that is arranged on the lateral surface of the tub and thatopens into the drying pocket. In the drying step, the humid air insidethe tub passes through the opening to enter the drying pocket andcondenses on the cold drying pocket surface.

In another embodiment of the present invention, the dishwasher comprisesa fan that enables the humid air inside the tub to be directed to thedrying pocket, thus providing an active drying process.

By means of the present invention, the heat of the water collected inthe drip tray is facilitated for cooling the drying pocket in the dryingstep before being discharged. The cold surface required for thecondensation of the humid air inside the tub in the drying step isobtained by using the water in the drip tray. The water in the driptray, that must be discharged to prevent the problems of overflowing andbad odors, is discharged after being used for increasing the dryingefficiency without consuming additional energy.

The dishwasher realized in order to attain the aim of the presentinvention is illustrated in the attached figures, where:

FIG. 1—is the schematic view of a dishwasher.

FIG. 2—is the schematic view of the tub and the drying pocket related toan embodiment of the present invention.

FIG. 3—is the schematic view of the tub lateral surface and the channelrelated to an embodiment of the present invention.

The elements illustrated in the figures are numbered as follows:

1. Dishwasher

2. Body

3. Tub

4. Drying pocket

5. Heat pump

6. First heat exchanger

7. Second heat exchanger

8. Compressor

9. Drip tray

10. Duct

11. Pump

12. Hole

13. Control unit

14. Channel

15. Inlet

16. Outlet

17. First valve

18. Second valve

19. Circulation pump

20. Opening

21. Fan

The dishwasher (1) comprises a body (2); a tub (3) that is disposedinside the body (2) and wherein the steps of washing, rinsing and dryingare realized; a drying pocket (4) that is disposed at least one lateralwall of the tub (3), that is in thermal contact with the tub (3) andthat provides the condensation of the humid air inside the tub (3) bybeing cooled in the drying step; a heat pump (5) that is disposed insidethe body (2), that provides the heating of the water to be used in thewashing step and that has a first heat exchanger (6) drawing heat fromthe ambient air, a second heat exchanger (7) transferring the heatreceived from the first heat exchanger (6) to the wash water and acompressor (8) fluidly connected to the first heat exchanger (6) and thesecond heat exchanger (7), realizing the refrigerant cycle, and a driptray (9) that is disposed immediately under the first heat exchanger(6), wherein the water condensing on the first heat exchanger (6) iscollected.

In the dishwasher (1), the articles to be washed are placed into the tub(3) and washed to be cleaned in the tub (3). After the washing step, thedrying pocket (4) is cooled, thus providing the condensation of thehumid air inside the tub (3). Moreover, in the dishwasher (1), therefrigerant at low temperature is passed over the first heat exchanger(6) and heat is transferred from the environment to the first heatexchanger (6) the surface of which is cooled down. The first heatexchanger (6) transfers the heat received from the environment to therefrigerant. The heat drawn from the environment by the first heatexchanger (6) is transferred to the second heat exchanger (7). Thesecond heat exchanger (7) transfer the heat drawn thereby to the washwater, thus enabling the heating of the wash water and this process iscarried out by passing the water to be used in the washing step to bepassed over the second heat exchanger (7) the surface of which heats up.At the same time, the ambient air condenses and leaves its moisture onthe first heat exchanger (6) the surface of which is cool. Thecondensing water flows down to be collected in the drip tray (9)disposed immediately under the first heat exchanger (6).

The dishwasher (1) of the present invention comprises a water duct (10)that extends between the drying pocket (4) and the drip tray (9) andthat is connected to the upper surface of the drying pocket (4), a pump(11) that is disposed on the water duct (10) and that enables the waterin the drip tray (9) to be delivered to the drying pocket (4), a hole(12) that is arranged on the drying pocket (4) and that opens into thetub (3) and a control unit (13) that enables the water collected in thedrip tray (9) to be delivered to the drying pocket (4), furtherproviding the discharge of the water in the drying pocket (4) into thetub (3) by means of the hole (12) by controlling the pump (11). Sincethe surface of the first heat exchanger (6) is cold during the heatingof the wash water, the water collected in the drip tray (9) is also coldwith respect to the environment. By controlling the pump (11), thecontrol unit (13) enables the water, that must be discharged in order toprevent overflowing or formation of bad odors, to be delivered to thedrying pocket (4) and the water flows over the drying pocket (4) andpreferably passes through the hole (12) arranged at the base of thedrying pocket (4) to be discharged to the tub (3). At this time, thewater that is cooler than the environment draws heat from the dryingpocket (4), thus enabling the cooling of the drying pocket (4). As thedrying pocket (4) becomes cooler, the condensation efficiency of thehumid air inside the tub (3) is improved. Thus, both the drip tray (9)is discharged and the efficiency of the drying step is increased.

In an embodiment of the present invention, the dishwasher (1) comprisesa channel (14) wherein the water transferred from the pump (11) ispassed so as to cool the drying pocket (4), the channel (14) beingdisposed on the drying pocket (4) and having an inlet (15) enabling thewater delivered to the drying pocket (4) to enter therein and an outlet(16) fluidly connected to the hole (12). The water transferred from thedrip tray (9) is delivered to the channel (14) preferably positioned onthe lateral surface of the drying pocket (4), thus the surfaces of thedrying pocket (4) are cooled. By passing the water through the channel(14), the surface of the drying pocket (4) is cooled with the surfacethereof not getting wet but remaining dry, thereby the time required forthe drying pocket (4) surfaces to reach saturation is increased,improving the condensation efficiency.

In another embodiment of the present invention, the channel (14) isdisposed on at least one surface of the tub (3) and the water deliveredby the pump (11) is passed through the channel (14). By disposing thechannel (14) on the lateral surface of the tub (3), the lateral surfaceof the tub (3) is cooled and the humid air, that cannot be transferredto the drying pocket (4) but remains in the tub (3), is enabled tocondense inside the tub (3), on the lateral surface of the tub (3).

In another embodiment of the present invention, the channel (14) is bentin serpentine form so as to cover at least one surface of the tub (3).By means of this embodiment, the area covered by the channel (14) on thetub (3) is increased and the water delivered by the pump (11) is enabledto cool a larger area. Thus, the humid air inside the tub (3) is enabledto be more efficiently condensed in the drying step.

In another embodiment of the present invention, the channel (14)surrounds the lateral surfaces of the tub (3) all around. By means ofthis embodiment, in the drying step, by increasing the surface area onthe tub (3) whereon the heat transfer is carried out, the condensationarea is prevented from being saturated and decreasing the dryingefficiency.

In another embodiment of the present invention, the dishwasher (1)comprises a first valve (17) that is connected to the inlet (15) and asecond valve (18) that is connected to the outlet (16) and both controlsthe flow of the water in the channel (14). When the first valve (17) andthe second valve (18) are open, the water delivered into the channel(14) flows along the channel (14) to be discharged. When the secondvalve (18) is closed, the water delivered into the channel (14) is keptwaiting in the channel before being discharged.

In an embodiment of the present invention, the control unit (13) keepsthe first valve (17) and the second valve (18) closed, thus enables thewater to be kept in the channel (14). After the pump (11) delivers thewater in the drip tray (9) to the channel (14), the control unit (13)changes the first valve (17) and the second valve (18) to the closedposition so that the water is kept waiting in the channel (14), thus byincreasing the heat exchange duration of the water and the channel (14)surfaces, the channel (14) is enabled to be cooled in a more efficientmanner.

In an embodiment of the present invention, the dishwasher (1) comprisesa circulation pump (19) that is disposed on the channel (14), that isfluidly connected to the channel (14) and that enables the water in thechannel (14) to be circulated in the channel (14). The control unit (13)changes the first valve (17) and the second valve (18) to the closedposition and the circulation pump (19) enables the water to becirculated in the channel (14). By means of this embodiment, even if asmall amount of water is collected in the drip tray (9), the watercollected is circulated in the channel (14), thus providing the coolingof all the surfaces of the channel (14).

In another embodiment of the present invention, the dishwasher (1)comprises an opening (20) that is arranged on the lateral surface of thetub (3) and that opens into the drying pocket (4). The humid air insidethe tub (3) enters the drying pocket (4) through the opening (20) andcondenses on the drying pocket (4) cooled by the water in the drip tray(9).

In another embodiment of the present invention, the dishwasher (1)comprises a fan (21) that directs the humid air inside the tub (3)towards the drying pocket (4) so as to pass through the opening (20). Bydirecting the humid air inside the tub (3) to the drying pocket (4), anactive drying process is carried out.

In the dishwasher (1) of the present invention, the water collected inthe drip tray (9) is facilitated for cooling the drying pocket (4) so asto increase the drying efficiency before being discharged.

1. A dishwasher comprising a body; a tub that is disposed inside thebody and wherein the steps of washing, rinsing and drying are realized;a drying pocket that is disposed at least one lateral wall of the tub,that is in thermal contact with the tub and that provides thecondensation of the humid air inside the tub by being cooled in thedrying step; a heat pump that is disposed inside the body, that providesthe heating of the water to be used in the washing step and that has afirst heat exchanger drawing heat from the ambient air, a second heatexchanger transferring the heat received from the first heat exchangerto the wash water and a compressor fluidly connected to the first heatexchanger and the second heat exchanger, realizing the refrigerantcycle, and a drip tray that is disposed immediately under the first heatexchanger, wherein the water condensing on the first heat exchanger iscollected, characterized by a water duct that extends between the dryingpocket and the drip tray, a pump that is disposed on the water duct andthat enables the water in the drip tray to be delivered to the dryingpocket, a hole that is arranged on the drying pocket and that opens intothe tub and a control unit that enables the water collected in the driptray to be delivered to the drying pocket, further providing thedischarge of the water in the drying pocket into the tub by means of thehole by controlling the pump.
 2. A dishwasher as in claim 1,characterized by a channel wherein the water transferred from the pumpis passed so as to cool the drying pocket, the channel being disposed onthe drying pocket and having an inlet enabling the water delivered tothe drying pocket to enter therein and an outlet fluidly connected tothe hole.
 3. A dishwasher as in claim 2, characterized by the channelthat is disposed on at least one surface of the tub.
 4. A dishwasher asin claim 3, characterized by the channel that is bent in serpentine formso as to cover at least one surface of the tub.
 5. A dishwasher as inclaim 3, characterized by the channel that surrounds the lateralsurfaces of the tub all around.
 6. A dishwasher as in claim 2,characterized by a first valve that is connected to the inlet and asecond valve that is connected to the outlet and both controls the flowof the water in the channel.
 7. A dishwasher as in claim 6,characterized by the control unit that keeps the first valve and thesecond valve closed, thus enables the water to be kept in the channel.8. A dishwasher as in claim 1, characterized by a circulation pump thatis disposed on the channel and that enables the water in the channel tobe circulated in the channel.
 9. A dishwasher as in claim 1,characterized by an opening that is arranged on the lateral surface ofthe tub and that opens into the drying pocket.
 10. A dishwasher as inclaim 9, characterized by a fan that directs the humid air inside thetub towards the drying pocket so as to pass through the opening.
 11. Adishwasher as in claim 4, characterized by the channel that surroundsthe lateral surfaces of the tub all around.
 12. A dishwasher as in claim3, characterized by a first valve that is connected to the inlet and asecond valve that is connected to the outlet and both controls the flowof the water in the channel.
 13. A dishwasher as in claim 4,characterized by a first valve that is connected to the inlet and asecond valve that is connected to the outlet and both controls the flowof the water in the channel.
 14. A dishwasher as in claim 5,characterized by a first valve that is connected to the inlet and asecond valve that is connected to the outlet and both controls the flowof the water in the channel.
 15. A dishwasher as in claim 2,characterized by an opening that is arranged on the lateral surface ofthe tub and that opens into the drying pocket.
 16. A dishwasher as inclaim 3, characterized by an opening that is arranged on the lateralsurface of the tub and that opens into the drying pocket.
 17. Adishwasher as in claim 4, characterized by an opening that is arrangedon the lateral surface of the tub and that opens into the drying pocket.18. A dishwasher as in claim 5, characterized by an opening that isarranged on the lateral surface of the tub and that opens into thedrying pocket.
 19. A dishwasher as in claim 6, characterized by anopening that is arranged on the lateral surface of the tub and thatopens into the drying pocket.
 20. A dishwasher as in claim 7,characterized by an opening that is arranged on the lateral surface ofthe tub and that opens into the drying pocket.